The agronomic and genetic biofortification of crops with selenium are novel strategies to improve the nutraceutical quality of staple crops. This review focuses on assessing the importance of Selenium in the development and crop production; as well as its effect in the antioxidant activity. In this regard, different revisions of the themes related to the presence of Selenium in the environment, soil and plant were carried out, emphasizing the concentration, the form of absorption and the metabolism of the element; additionally, the importance of agronomic and genetic biofortification in agricultural crops. Studies have shown that Selenium stimulates the synthesis of proteins, amino acids, nitrogen secondary compounds, phenolic compounds, likewise increases antioxidant activity, and it is associated with the prolongation of the shelf life of horticultural products. Biofortification with Selenium in agricultural crops is increasingly becoming a solution to improve the problem of trace element deficiency in the human population as well as to increase the content of bioactive compounds.